Dibromoacetic acid (DBA) is a water disinfection byproduct formed by the reaction of chlorine oxidizing compounds with natural organic matter in water containing bromide. Male and female F344/N rats and B6C3F(1) mice were exposed to DBA in drinking water for 2 weeks (N=5), 3 months (N=10), or 2 years (N=50). Concentrations of DBA in drinking water were 0, 125, 250, 500, 1000, and 2000mg/L in the 2-week and 3-month studies, and 0, 50, 500, and 1000mg/L in the 2-year studies. Toxic effects of DBA in the prechronic studies were detected in the liver (hepatocellular cytoplasmic vacuolization in rats and mice) and testes (delayed spermiation and atypical residual bodies in male rats and mice, and atrophy of the germinal epithelium in rats). In the 2-year studies, neoplasms were induced at multiple sites in rats and mice exposed to DBA; these included mononuclear cell leukemia and abdominal cavity mesothliomas in rats, and neoplasms of the liver (hepatocellular adenoma or carcinoma and hepatoblastoma) and lung (alveolar adenoma or carcinoma) in mice. The increase in incidence of hepatocellular neoplasms in male mice was significant even at the lowest exposure concentration of 50mg/L, which is equivalent to an average daily dose of approximately 4mg/kg. These studies provide critical information for future re-evaluations of health-based drinking water standards for haloacetic acids.

中文翻译：

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水消毒副产物二溴乙酸对大鼠和小鼠的毒性和致癌性。


二溴乙酸（DBA）是氯氧化化合物与含溴化物水中的天然有机物反应形成的水消毒副产物。将雄性和雌性F344/N大鼠和B6C3F(1)小鼠暴露于含DBA的饮用水中2周(N=5)、3个月(N=10)或2年(N=50)。在为期2周和3个月的研究中，饮用水中DBA的浓度为0、125、250、500、1000和2000mg/L，在2年的研究中为0、50、500和1000mg/L。在慢性前期研究中，在肝脏（大鼠和小鼠的肝细胞胞质空泡化）和睾丸（雄性大鼠和小鼠的精子形成延迟和非典型残留体，以及大鼠的生发上皮萎缩）中检测到DBA的毒性作用。在为期 2 年的研究中，暴露于 DBA 的大鼠和小鼠在多个部位诱发了肿瘤；这些包括大鼠的单核细胞白血病和腹腔间皮瘤，以及小鼠的肝脏肿瘤（肝细胞腺瘤或癌和肝母细胞瘤）和肺部肿瘤（肺泡腺瘤或癌）。即使在最低暴露浓度50mg/L（相当于日均剂量约4mg/kg）下，雄性小鼠肝细胞肿瘤的发生率也显着增加。这些研究为未来重新评估卤乙酸健康饮用水标准提供了重要信息。